In a retrospective cohort study reported in JAMA Oncology, Hagen F. Kennecke, MD, and colleagues found that among U.S. patients with clinical stage II/III rectal cancer diagnosed between 2006 and 2016 who received trimodality therapy, use of postoperative chemoradiation therapy (CRT) decreased and use of preoperative CRT and postoperative multiagent chemotherapy increased over time. These changes were accompanied by improved pathologic downstaging and survival.
Study Details
The study involved National Cancer Database data on patients diagnosed between 2006 and 2016 who received trimodality therapy. Trimodality therapy components included definitive surgery, radiotherapy alone or in combination with chemotherapy, and neoadjuvant or adjuvant single-agent or multiagent chemotherapy independent of radiotherapy.
Key Findings
Among 32,467 patients receiving trimodality therapy over the study period:
- 8,883 (27%) received total neoadjuvant therapy (TNT; including multiagent chemotherapy only)
- 5,967 (18%) received preoperative CRT plus postoperative single-agent chemotherapy
- 12,926 (40%) received preoperative CRT plus postoperative multiagent chemotherapy
- 4,689 (14%) received postoperative CRT plus multiagent chemotherapy.
Between 2006 and 2016, use of postoperative CRT decreased from 28% to 8% of patients (P < .001), whereas use of preoperative CRT and postoperative multiagent chemotherapy increased from 24% to 45% (P < .001). Use of preoperative CRT and postoperative single-agent chemotherapy increased from 14% to 25% (P < .001) and use of TNT decreased from 34% to 23% (P < .001).
No significant change in clinical stage II and III distribution was observed over time. Excluding the postoperative CRT plus multiagent chemotherapy cohort, overall pathologic stage (0, I, II, III) progressively downstaged from 1%, 10%, 31%, and 57% in 2006 to 3%, 22%, 29%, and 45% in 2016, respectively (overall P < .001).
Among 24,297 patients diagnosed between 2006 and 2015 with available survival data, the adjusted hazard ratio for mortality within 36 months after diagnosis was 0.77 (95% confidence interval = 0.67–0.87) for 2015 vs 2006.
The investigators concluded, “In this cohort study, the shift toward preoperative CRT and lower pathologic stage was associated with improved overall survival in stage II/III rectal cancers.”
Dr. Kennecke, of Portland Providence Cancer Institute and Earle A. Chiles Research Institute, is the corresponding author for the JAMA Oncology article.
Disclosure: For full disclosures of the study authors, visit jamanetwork.com.
